1. Field of the Invention
This invention relates to a globe-mounting apparatus for explosion-proof lighting devices.
Since the above-mentioned explosion-proof lighting devices are employed at places such as oil refineries where there exists a constant danger of explosion, the inside of a lighting body is structured airtight, and the body and the globe members are built very thick and strong so that it will not discharge electricity outside of the lighting body, even if the electric bulb inside it is broken. Moreover, a packing is mounted on the plane where the lighting body and the flange part of the globe meet each other, and the two parts are fixed to each other by bolts. Because of this, an electric bulb cannot be replaced by another unless all of the above bolts are drawn out. Usually about 6-8 of these fixing bolts are employed, and the replacement of electric bulbs located at the ceilings or pillars is a highly difficult operation, especially since the weight of explosion-proof lighting devices is very heavy, the globe part alone weighing more than 10 kg. Accordingly, if there is no connecting structure between the lighting body and the globe members other than the above fastening bolts, there is always a danger that the globe will drop when the bolts become loose.
2. Brief Description of the Prior Art
In conventional explosion-proof lighting devices, the globe members and the lighting body are connected by a hinge, but there is always a possibility that the globe members will drop when the fastening bolts are loosened, which means that the whole weight of the globe is suddenly on the hinge alone, causing it to be damaged. Thus, when the bolts are to be loosened, an extra person is needed to support the globe other than the one who loosens the bolts. In case there is only one person to do the whole replacing operation, he has to support the globe members with one hand, while loosening the bolts with another. Accordingly, it is required of him to support the weight of more than 10 kg. with one hand until he finishes drawing out all the bolts. This, naturally, is a highly dangerous operation which cannot be easily accomplished.
In view of the fact that the explosion-proof lighting devices are usually mounted in high places intricated with pipes, angles, etc., and because globe members are in general very weighty, it is necessary to employ a number of workers to safely perform the replacement of electric bulbs.